Cockpit recording erased following near-crash

Cougar Helicopters says it was not aware data had to be protected

After one of its helicopters nearly crashed into the North Atlantic on July 23, 2011, and recovered about 11 metres from the water’s surface, Cougar Helicopters launched an internal investigation to find out what went wrong.

That task was made more difficult by an absence of key information from the aircraft’s cockpit recorder, as the federal Transportation Safety Board (TSB) stated, following its own investigation.

The Sikorsky S-92 helicopter involved was equipped with a multipurpose flight recorder from manufacturer Penny and Giles. In two separate streams, it records both flight data and cockpit voice recorder data, taking on 25 hours of flight data and two hours from the cockpit, before overwriting.

“The multipurpose flight recorder was not immediately secured following the occurrence,” the TSB stated in its report on the close call.

The report was released publicly Thursday.

“Instead, an engine wash was carried out along with some routine maintenance tasks. It was not until after this additional work had been done on the helicopter that the (recorder) data was downloaded by Cougar Helicopters,” it stated.

“As a result of these delays in preserving the (recorder) data, all cockpit voice recorder data for the occurrence was overwritten.”

Flight data was recovered, but the only cockpit tape remaining was for the flight back to St. John’s — after the helicopter had returned to its cruising altitude.

The lack of information from the cockpit, “made it difficult for investigators to analyze the actions of the flight crew during the occurrence,” the TSB noted.

“At the time of the occurrence, Cougar Helicopters did not have a cockpit voice recorder protection policy or procedure in effect.”

Company staff were the first to discover that the voice recorder data from the cockpit was lost. The team assigned to the internal investigation and data monitoring sought to listen to the recording.

“The operator was unaware that the cockpit voice recorder is privileged under the Canadian Transportation Accident Investigation and Safety Board Act,” the TSB found.

And yet, flight recorder data was part of the investigation into the crash of a Cougar Helicopters flight and resulting death of 17 people in March 2009.

Following its investigation into that crash, in a report released in February 2011, the TSB stated, “The International Civil Aviation Organization’s Annex 13 (guidance for aircraft accident and incident investigation) requires states conducting accident investigations to protect cockpit voice recordings. Canada complies with this requirement by making all on-board recordings, including cockpit voice recorders, privileged in the Canadian Accident Investigation and Safety Board Act.”

The TSB emphasized the value of the cockpit voice recordings in its report on the crash.

“In order to validate the safety issues raised in this investigation, the TSB has made extensive use of the available cockpit voice recorder information in its report,” it stated.

The report was publicly released about five months prior to the 2011 near-crash.

According to the Canadian Transportation Accident Investigation and Safety Board Act, “Any on-board recording that relates to a transportation occurrence being investigated under this Act shall be released to an investigator who requests it for the purposes of the investigation.”

In this case, the cockpit recording was requested, but could not be made available.

Meanwhile, the TSB report noted there was an earlier case of a rapid descent and near-crash involving a Cougar Helicopters flight, on Aug. 26, 2007. The event was investigated internally, but was not reported to the TSB at the time, despite that report being required under existing regulation.

In the 2007 case, with poor visibility, the helicopter missed an approach to the Hibernia gravity-base structure and the pilot decided to make a second attempt. The aircraft’s nose tipped up, airspeed dropped rapidly and the aircraft’s rate of descent ran up, peaking at 790 feet per minute.